Process using hydrocyclones

Abstract

The present invention concerns a process for preparing of slurries containing suspended and dissolved particles and a solution as well as a slurry are provided onto a hydrocyclone equipment, disk centrifuge or nozzle centrifuge equipment. The dry matter concentration in the collected slurry is higher than the concentration of the mixture of the slurry and the solution as such. The use of a hydrocyclone stage for this specific purpose is disclosed as well.

The invention claimed is: 
     
       1. A process for preparation of slurries containing suspended and dissolved particles, said process comprising the following steps:
 a. providing a solution (A) of dissolved particles (A′), 
 b. providing a slurry (B) of suspended particles (B′), 
 c. introducing solution (A) and slurry (B) into a battery of hydrocyclone stages containing at least two hydrocyclone stages, wherein the solution (A) and the slurry (B) are separately introduced at different stages of the battery of hydrocyclone stages; and 
 d. collecting a slurry (B″) containing at least a part of dissolved particles (A′) and at least a part of suspended particles (B′); 
 wherein the collected slurry (B″) has a total dry matter concentration of the suspended particles (B′) and dissolved particles (A′) that is at least 3% higher than the combined dry matter concentration of solution (A) and slurry (B). 
 
     
     
       2. The process according to  claim 1 , wherein the slurry (B) is a slurry of starch and/or starch derivatives. 
     
     
       3. The process according to  claim 1 , wherein the dissolved particles (A′) comprise one or more catalysts, reagents and/or reaction aids. 
     
     
       4. The process according to  claim 1 , wherein the dissolved particles (A′) comprise salts. 
     
     
       5. The process according to  claim 1 , wherein the suspended particles are selected from the group consisting of native starches or modified starches selected from the group consisting of crosslinked starches, acetylated starches, hydroxyethylated and hydroxypropylated starches, inorganically esterified starches, oxidized starches, zwitterionic starches, starches modified by enzymes, and combinations thereof. 
     
     
       6. The process according to  claim 1 , wherein the battery of hydrocyclone stages comprises a number of hydrocyclone stages selected from the group consisting of six hydrocyclone stages, seven hydrocyclone stages, eight hydrocyclone stages, nine hydrocyclone stages, ten hydrocyclone stages, eleven hydrocyclone stages and twelve hydrocyclone stages. 
     
     
       7. The process according to  claim 6 , wherein the solution (A) is introduced at the penultimate stage of the battery of hydrocyclone stages and the slurry (B) is introduced at approximately the middle stage of the battery of hydrocyclone stages. 
     
     
       8. A process for preparation of slurries containing suspended and dissolved particles, said process comprising the following steps:
 a. providing a solution (A) of dissolved reaction aids (A′); 
 b. providing a slurry (B) of starch and/or starch derivatives (B′); 
 c. introducing solution (A) and slurry (B) into a battery of hydrocyclone stages containing at least two hydrocyclone stages, wherein the solution (A) and the slurry (B) are separately introduced at different stages of the battery of hydrocyclone stages; and 
 d. collecting slurry (B″) of starch and/or starch derivatives containing at least 10% weight of total weight of dissolved reaction aids (A′) present in solution (A); 
 e. collecting solution (A″) containing a maximum of 90% weight of total weight of dissolved reaction aids (A′) present in solution (A); 
 wherein the collected slurry (B″) has a total dry matter concentration of the starch and/or starch derivatives (B′) and dissolved reaction aids (A′) that is at least 3% higher than the combined dry matter concentration of solution (A) and slurry (B). 
 
     
     
       9. The process according to  claim 8 , wherein the collected slurry (B″) contains at least 90% by weight of the initial starch and/or starch derivatives (B′). 
     
     
       10. The process according to  claim 8 , wherein solution (A″) is recycled into step (a) as a component of solution (A). 
     
     
       11. The process according to  claim 8 , wherein solution (A″) is concentrated to a higher dry matter concentration of dissolved reaction aids (A′), and recycled into step (a) as a component of solution A. 
     
     
       12. The process according to  claim 8 , wherein slurry (B″) is applied in a starch modification process. 
     
     
       13. The process according to  claim 12 , wherein the starch modification process is an oxidation, acidification, esterification, etherification, crosslinking reaction, alkylation, hydroxyalkylation, hydrolyzation or a combination thereof. 
     
     
       14. The process according to  claim 8 , wherein solution (A) of dissolved reaction aids (A′) is recuperated from a starch modification process. 
     
     
       15. The process according to  claim 8 , wherein the starch and/or starch derivatives are selected from the group consisting of native starches or modified starches selected from the group consisting of crosslinked starches, acetylated starches, hydroxyethylated and hydroxypropylated starches, inorganically esterified starches, oxidized starches, zwitterionic starches, starches modified by enzymes, and combinations thereof. 
     
     
       16. The process according to  claim 8 , wherein the battery of hydrocyclone stages comprises a number of hydrocyclone stages selected from the group consisting of six hydrocyclone stages, seven hydrocyclone stages, eight hydrocyclone stages, nine hydrocyclone stages, ten hydrocyclone stages, eleven hydrocyclone stages and twelve hydrocyclone stages. 
     
     
       17. The process according to  claim 16 , wherein the solution (A) is introduced at the penultimate stage of the battery of hydrocyclone stages and the slurry (B) is introduced at the middle stage of the battery of hydrocyclone stages.